UPTAKE OF I-123 BMIPP IN THE NORMAL HEART WITH EXERCISE

15-(p-[I-123] -iodophenyl)-3-R,S-methylpentadecanoic acid (I-123-BMIPP ) is a modified branched fatty acid analogue with relatively slow clea rance from the heart which renders it suitable to study myocardial fat ty acid metabolism with single photon emission computed tomography (SP ECT), Myocardial fatty acid uptake is regulated by a variety of factor s; including concentrations of potential substrates, cardiac workload and possible ischaemia, Since these factors could be altered by exerci se, the purpose of this study was to compare I-123-BMIPP uptake at res t and with exercise in 10 healthy male volunteers. I-123-BMIPP (185 MB q) was administered intravenously followed by planar and tomographic i maging with a dual-headed scintillation camera. A geometrical mean met hod including the triple-energy scatter correction technique was used to quantify myocardial uptake using the planar images, The mean uptake s with respect to the administered dose for the rest and exercise stud ies were 4.62 +/- 0.98% and 3.02 +/- 0.58%, respectively, The mean dif ference was 1.60 +/- 0.83% and the 95% confidence interval was 1.00 - 2.19%, The global myocardial uptake of I-123-BMIPP was significantly r educed from rest to exercise, but regional redistribution was not obse rved during the visual interpretation of the images.